Acceptability of traffic network management

In today’s urban traffic network management, the interests of individual road users are often overlooked, as are their travel choice behaviour and cognitive abilities. This research contributes to knowledge about trade-offs between conflicting interests and objectives, by combining insights from traffic management, travel choice behaviour and traffic psychology disciplines.

An important set of assumptions, derived from standard economics, often made in transportation modeling states that people are rational, that they are perfectly informed about their decisions, that they can calculate the value of the different options available, and that they are cognitively unhindered in weighting the implications of each potential choice. In other words: people are presumed to be making logical and sensible decisions. Moreover, when a wrong decision is made or when conditions change from time to time, the standard economics perspective suggests that people will quickly learn and respond. On the basis of these assumptions, traffic engineers have drawn far-reaching conclusions about travel choice behavior, which are the basis for many of the models used today.

Behavioral economics draw on the aspects of both (cognitive) psychology and economics, and study the motives and behaviors that explain deviations from rational behavior. It is not just the behavior that is on interest, but also the decision-making process behind such behavior. Human irrationality is about our distance from perfection. Recent studies provide evidence that these irrational behaviors are neither random nor senseless. They are systematic, consistent, repetitive, and therefore predictable.

Building upon this knowledge, this research introduces the concept of ‘regulation flexibility’. This concept assists road operators and traffic engineers by describing the range in which traffic management measures are most effective. On the one hand regulation flexibility outlines when undesired behavioral response can be expected, while on the other hand it may serve as a target that needs to be exceeded to evoke desired behavioral response. The concept assumes that travelers are only inclined to alter their choice when a change in the transportation system or their trip, for example traffic light delay, is larger than some individual-situation-specific threshold. Or put the other way around: travellers do not alter their choice when a change remains below this threshold.

The aim of this research is to determine the boundaries of regulation flexibility using empirical data. Emphases is on the hypothesis that travelers’ ability to detect changes in attributes of their trip, or the performance of a traffic system is limited. Furthermore, even when a change is detected, traveler’s indifference to this change may prevent a response. The main question of research is how these factors add up to the thresholds mentioned earlier, and what magnitude of change evokes behavioral response.